Sleeve-like stoppers are widely used in association with tubing sets and containers used in the administration of intravenous solutions to patients. These types of stoppers ordinarily include a pierceable membrane portion and a side wall portion. The stopper is attached to a port on the tubing set, container, or other device such that the pierceable membrane sealingly covers the port. The side wall portion retains the pierceable membrane portion on the port. Fluids can be introduced into and/or withdrawn from the tubing set, container, or device by inserting a piercing member, e.g., a needle or a cannula, through the pierceable membrane, thereby providing fluid communication between the interior of the tubing set, container, or device and the exterior environment thereof.
In medical applications, sleeve stoppers of this type allow medical personnel to withdraw finite amounts of fluid from the tubing set or medical container without compromising the sterility of the fluid. It will be appreciated that standard medical cannulas, including, but not limited to, hypodermic syringes, can be used to pierce the pierceable membrane and provide the necessary fluid communication across the membrane. Such stoppers are particularly useful in connection with the addition of fluids into tubing sets and medical containers. For example, when used in connection with a Y-port on a medical tubing set, as depicted in FIG. 1, the sleeve stopper can be used to seal an "add port" on the Y-port device. A medical professional can introduce a secondary fluid into the tubing set for delivery to a patient by simply inserting a piercing member through the pierceable membrane and flowing a fluid into the tube set. Sleeve stoppers of this type also are useful to dilute medicaments or to facilitate the mixing of two or more fluids in containers of known construction.
A heretofore known sleeve stopper of the above-discussed type has a generally stepped, cylindrical configuration, including male and female portions. The male portion is configured to be received within a tubular port of a tubing set or a container, while the female portion, in turn, is of a relatively larger size and is configured to receive therein a wall defining tubular port. In this way, the sleeve stopper can be used to fluidly seal a port associated with the tubing set or container. In such an arrangement, the male portion has an outside diameter at its free end which is less than the inside diameter of the end of the female portion when the sleeve stopper is in its first position, that is, the position reflected in FIG. 2.
By virtue of this relative dimensioning, a problem can occur attendant to manufacture and handling of adjacent sleeve stoppers. In particular, undesired "snaking" of the stoppers can occur when the male portion of one stopper telescopically nests within the female portion of an adjacent stopper. This effect can create an elongated "snake" of stopper parts, and can detract from efficient operation of automatic handling equipment.